Image pickup element, image pickup device, manufacturing device and method

ABSTRACT

There is provided an image pickup element including a non-planar layer having a non-planar light incident surface in a light receiving region, and a microlens of an inorganic material which is provided on a side of the light incident surface of the non-planar layer, and collects incident light.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/398,257, filed Oct. 31, 2014, which is a National Stage Entry ofApplication No.: PCT/JP2013/064222, filed May 22, 2013, which claims thebenefit of priority from Japanese Patent Application No. 2012-237371,filed Oct. 29, 2012 and Japanese Patent Application No. 2012-122851,filed May 30, 2012, the entire contents of each of which areincorporated herein by reference.

TECHNICAL FIELD

The present technology relates to image pickup elements, image pickupdevices, manufacturing devices and methods, and more particularly, to animage pickup element, image pickup device, manufacturing device andmethod which can reduce deterioration of sensitivity characteristics.

BACKGROUND ART

Conventionally, a solid-state image pickup device, which includes alarge number of image pickup regions, and an optical element havingmicrolenses etc., on a semiconductor wafer, is hermetically molded afterelectrical interconnects have been formed, and is used as a photosensorfor digital video equipment, such as a digital still camera, a camerafor a mobile telephone, a digital camcorder, etc.

Various methods have been proposed as a method for manufacturing such asolid-state image pickup device (see, for example, Patent Literature 1and Patent Literature 2).

Patent Literature 1 discloses a method for manufacturing a microlens inwhich a gap between each microlens made of inorganic film is reduced,and a distance from a photodiode to the microlens is reduced, therebyimproving sensitivity characteristics of a solid-state image pickupelement.

Patent Literature 2 discloses a method for manufacturing a microlensincluding two layers.

CITATION LIST Patent Literature

Patent Literature 1: JP 2008-009079A

Patent Literature 2: JP 2008-277800A

SUMMARY OF INVENTION Technical Problem

However, in the case of the method described in Patent Literature 1, amiddle layer is also used to transfer its shape to a lens material layerby etching, and therefore, it takes a longer time to perform theetching. This etching process is performed by plasma etching, andtherefore, the plasma damage adversely affects the solid-state imagepickup device. Specifically, dark-current characteristics etc. of thesolid-state image pickup element deteriorate due to the longer etchingtime. At the same time, the long processing time increases variations inetching on a semiconductor wafer substrate surface or between wafersubstrates, which causes variations in the position in thecross-sectional direction of the microlens, leading to the risk ofreduction of the sensitivity characteristics of the solid-state imagepickup element.

The microlens with high light collection power which is formed by themethod described in Patent Literature 2 is a gapless microlens which isformed by adjusting the film formation of the microlens in the secondlayer so that there is not a gap between each microlens. However, whenthe micro in the second layer is formed so that a gap of the microlensin the first layer having a gap is reduced, the position of themicrolens which is finally formed is raised (further away from thephotodiode surface), and therefore, it is likely that the sensitivitycharacteristics etc. of a solid-state image pickup device in which thedistance between the photodiode and the microlens is reduced as in, forexample, a back-illuminated solid-state image pickup device, cannot beimproved.

With these circumstances in mind, the present technology has beenproposed, and it is an object of the present technology to reduce thedeterioration of the sensitivity characteristics.

Solution to Problem

According to a first aspect of the present technology, there is providedan image pickup element including a non-planar layer having a non-planarlight incident surface in a light receiving region, and a microlens ofan inorganic material which is provided on a side of the light incidentsurface of the non-planar layer, and collects incident light.

The microlens may include a plurality of layers.

The layers of the microlens including the plurality of layers may havedifferent refractive indices.

The layers of the microlens including the plurality of layers may havedifferent curved surface shapes.

At least a portion of the layers of the microlens including theplurality of layers may be formed in a recess portion of the non-planarlayer.

An anti-reflection film may be formed over a light incident surface ofthe microlens.

An adhesive material layer provided on a side of a light incidentsurface of the microlens may be further included.

The non-planar layer may have a filter.

The filter may include filters with a plurality of colors havingdifferent thicknesses in a direction in which light passes.

In the filter, filters having different thicknesses and corresponding tored, green, and blue pixels, may be arranged in a Bayer arrangement, andthe green filters may be linked between pixels.

The filter may be formed of an organic material.

The non-planar layer may have an organic film which is formed on thefilter and has a non-planar light incident surface.

Heights of projections and recesses of a light incident surface of theorganic film may be lower than heights of projections and recesses of alight incident surface of the filter.

The refractive index of the organic film may be between the refractiveindex of the filter and the refractive index of the microlens.

The non-planar layer may have an inter-pixel light shield film.

The non-planar layer may have projections and recesses on the lightincident surface due to a difference in height between the filter andthe inter-pixel light shield film.

A chip size package structure may be formed.

According to a second aspect of the present technology, there isprovided an image pickup device including an image pickup element whichcaptures an image of an object, and outputs the image of the object asan electrical signal, and an image processing unit which processes theimage of the object obtained by the image pickup element. The imagepickup element includes a non-planar layer which has a non-planar lightincident surface in a light receiving region, and a microlens of aninorganic material which is provided on a side of the light incidentsurface of the non-planar layer, and collects incident light.

According to a third embodiment of the present technology, there isprovided a manufacturing device including a non-planar layer formingunit which forms a non-planar layer having a non-planar light incidentsurface in a light receiving region of an image pickup element, aninorganic film forming unit which forms an inorganic film on a side ofthe light incident surface of the non-planar layer formed by thenon-planar layer forming unit, a planarization film forming unit whichforms a planarization film on a side of a light incident surface of theinorganic film formed by the inorganic film forming unit, a resistforming unit which forms a resist on a side of a light incident surfaceof the planarization film formed by the planarization film forming unit,a thermal reflow process unit which performs a thermal reflow process onthe image pickup element on which the resist has been formed by theresist forming unit, and an etching process unit which performs etchingon the image pickup element on which the thermal reflow process has beenperformed by the thermal reflow process unit.

According to the third embodiment of the present disclosure, there isfurther provided a method for manufacturing a manufacturing device whichmanufactures an image pickup element, the method including by themanufacturing device, forming a non-planar layer having a non-planarlight incident surface in a light receiving region of an image pickupelement, forming an inorganic film on a side of the light incidentsurface of the non-planar layer formed, forming a planarization film ona side of a light incident surface of the inorganic film formed, forminga resist on a side of a light incident surface of the planarization filmformed, performing a thermal reflow process on the image pickup elementon which the resist has been formed, and performing etching on the imagepickup element on which the thermal reflow process has been performed.

According to the first aspect of the present technology, a non-planarlayer having a non-planar light incident surface in a light receivingregion, and a microlens of an inorganic material which is provided onthe light incident surface of the non-planar layer, and collectsincident light, are included.

According to the second aspect of the present technology, an imagepickup element which captures an image of an object, and outputs theimage of the object as an electrical signal, and an image processingunit which processes the image of the object obtained by the imagepickup element, are included. The image pickup element includes anon-planar layer which has a non-planar light incident surface in alight receiving region, and a microlens of an inorganic material whichis provided on the light incident surface of the non-planar layer, andcollects incident light.

According to the third aspect of the present technology, a non-planarlayer is formed which has a non-planar light incident surface in a lightreceiving region of an image pickup element, an inorganic film is formedon the light incident surface of the non-planar layer formed, aplanarization film is formed on a light incident surface of theinorganic film formed, a resist is formed on a light incident surface ofthe planarization film formed, a thermal reflow process is performed onthe image pickup element on which the resist has been formed, andetching is performed on the image pickup element on which the thermalreflow process has been performed.

Advantageous Effects of Invention

According to the present technology, deterioration of the sensitivitycharacteristics can be reduced.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing an example configuration of a portion of thelayers of an image pickup element.

FIG. 2 is a diagram for describing a shift of an in-focus position.

FIG. 3 is a diagram showing an example main configuration of an imagepickup device.

FIG. 4 is a diagram showing an example configuration of color filters.

FIG. 5 is a diagram showing an example configuration of a portion of thelayers of an image pickup element.

FIG. 6 is a diagram showing an example configuration of a portion of thelayers of an image pickup element.

FIG. 7 is a diagram showing an example configuration of a portion of thelayers of an image pickup element.

FIG. 8 is a diagram showing an example configuration of a multi-layermicrolens.

FIG. 9 is a diagram showing an example of each layer of a multilayermicrolens.

FIG. 10 is a diagram showing an example of each layer of a multilayermicrolens.

FIG. 11 is a diagram showing an example of each layer of a multilayermicrolens.

FIG. 12 is a diagram showing an example of each layer of a multilayermicrolens.

FIG. 13 is a diagram showing an example of each layer of a multilayermicrolens.

FIG. 14 is a diagram showing an example of each layer of a multilayermicrolens.

FIG. 15 is a block diagram showing an example main configuration of amanufacturing device.

FIG. 16 is a flowchart for describing an example flow of a manufactureprocess.

FIG. 17 is a diagram for describing how a manufacture process isperformed.

FIG. 18 is a diagram for describing an example film pressure ratio.

FIG. 19 is a diagram for describing an example mean free path.

FIG. 20 is a diagram for describing example spherical surfacecorrection.

FIG. 21 is a diagram showing an example in which an anti-reflection filmis applied.

FIG. 22 is a diagram for describing an example refractive index of anadhesive agent.

FIG. 23 is a diagram showing an example in which an inter-pixel lightshield film is applied.

FIG. 24 is a diagram showing an example in which an inter-pixel lightshield film is applied.

FIG. 25 is a block diagram showing another example configuration of amanufacturing device.

FIG. 26 is a flowchart for describing another example flow of amanufacture process.

FIG. 27 is a diagram for describing another example of how a manufactureprocess is performed.

FIG. 28 is a diagram showing an example configuration of a portion ofthe layers of an image pickup element.

FIG. 29 is a block diagram showing still another example configurationof a manufacturing device.

FIG. 30 is a flowchart for describing still another example flow of amanufacture process.

FIG. 31 is a diagram for describing still another example of how amanufacture process is performed.

FIG. 30 is a diagram showing an example configuration of a portion ofthe layers of an image pickup element.

FIG. 33 is a diagram showing an example configuration of a portion of animage pickup element.

FIG. 34 is a block diagram showing an example main configuration of animage pickup device.

FIG. 35 is a block diagram showing an example main configuration of acomputer.

DESCRIPTION OF EMBODIMENTS

Embodiments for carrying out the present disclosure (hereinafterreferred to as embodiments) will now be described. Note that thedescription will be given in the following order.

1. First Embodiment (Image Pickup Device)

2. Second Embodiment (Manufacturing Device, Manufacturing Method)

3. Third Embodiment (Manufacturing Device, Manufacturing Method)

4. Fourth Embodiment (Image Pickup Device)

5. Fifth Embodiment (Computer)

1. First Embodiment 1-1 CSP

A solid-state image pickup device, which includes a large number ofimage pickup regions, and an optical element having microlenses etc., ona semiconductor wafer, is hermetically molded after electricalinterconnects have been formed, and is used as a photosensor for digitalvideo equipment, such as a digital still camera, a camera for a mobiletelephone, a digital camcorder, etc.

FIG. 1 shows an example configuration of microlenses and color filtersin a solid-state image pickup element. In the example of FIG. 1, filtershaving different colors of the color filters have different thicknesses,and therefore, projections and recesses are formed on the light incidentsurface of the color filters Therefore, a planarization film is formedon the light incident surface to planarize the light incident surface.The microlenses are formed on the light incident surface of theplanarization film.

Cross-sectional views shown in A of FIG. 1 and B of FIG. 1 havedifferent cross-sectional directions. A thickness from the bottomsurface of the color filter to the bottom surface of the microlens inthe cross-sectional view shown in A of FIG. 1 is t1, and a thicknessfrom the bottom surface of the color filter to the bottom surface of themicrolens in the cross-sectional view shown in B of FIG. 1 is t2.

In order to achieve the recent smaller size, thinner size, andhigher-density implementation of video equipment, the chip size package(CSP) technique, which is a technique of establishing electricalconnections by forming through electrodes and redistribution linesduring an assembly process on the wafer, has been studied as thestructure of a solid-state image pickup device, instead of theceramic-type or plastic-type package, in which electrical connectionsare established by traditional die bonding and wire bonding.

FIG. 2 shows how incident light is collected by a microlens, passesthrough the color filter, and focused onto the photodiode. From theviewpoint of the light collection characteristics, the refractiveindices of the microlens and an adhesive material 1 are required tosatisfy the following relationship.

Microlens>Adhesive Material 1

As shown in FIG. 2, the incident light to the solid-state image pickupelement includes perpendicular incident light and oblique incident lightcontaining a perpendicular component and an oblique component. The lightcollection characteristics with respect to the perpendicular incidentlight to the photodiode can be adjusted by changing the radius ofcurvature (r) of the arc-shaped microlens. However, for the obliqueincident light, the focus position of the perpendicular incident lightis shifted. In order to reduce the amount of the shift, it is necessaryto reduce the layer thickness. By reducing the layer thickness to adjustthe radius of curvature of the microlens, the sensitivitycharacteristics or luminance shading of the solid-state image pickupelement are improved.

When the CSP structure is employed as the package structure of asolid-state image pickup element, there is typically an empty space onthe microlens. The refractive index of the microlens is about 1.50 to1.6 when the microlens is made of a typical resin, such as anacrylic-based resin or a styrene-based resin. Therefore, the lightcollection characteristics are determined, from the refractive index of1.0 of air, by the microlens having a refractive index of about 1.5 to1.6 (the refractive index difference Δn: about 0.5 to 0.6).

However, when the CSP structure is employed, then if the adhesivematerial 1 formed on the microlens contains fluorine in itsacrylic-based resin or siloxane-based resin, the refractive index isabout 1.4 to 1.43. Alternatively, when the acrylic-based resin or thesiloxane-based resin contains hollow silica, the refractive index isabout 1.3 to 1.4. Here, when the microlens is made of a material ofabout 1.5 to 1.6 as described above, Δn is about 0.07 to 0.3, andtherefore, the light collection power of the microlens is likely todecrease. If the light collection power decreases, the focal length ofthe microlens increases, and therefore, it is necessary to increase thelayer thickness of FIG. 2, leading to the risk of deterioration of thesensitivity characteristics of the solid-state image pickup elementhaving the increased thickness.

As described above, when the adhesive material 1 is made of a materialhaving a refractive index of about 1.3 to 1.43, it is necessary to setthe refractive index of the microlens to about 1.8 to 2.03 in order toachieve light collection power similar to when the CSP structure is notemployed (there is air on the microlens). The microlens is also requiredto have high transparency with respect to visible light (400 to 700 nm).There is not a single organic material which has these characteristicsin terms of refractive index and transparency. In contrast to this, arefractive index which can be improved by adding fine particles of ametal oxide, such as, for example, zinc oxide, zirconium oxide, niobiumoxide, titanium oxide, tin oxide, etc., into a polyimide-based resin, asiloxane-based resin, a phenol-based resin, etc., can be adjusted basedon the amount of the fine metal oxide particles which are added, and canbe adjusted to about 1.6 up to about 2.0.

In addition the above technique of adding fine particles of a metaloxide into an organic material, silicon oxynitride film (SiON) orsilicon nitride film (SiN), which are typically used in semiconductormanufacturing processes, can be used as a material which has both arefractive index and transparency.

However, when inorganic film, such as silicon oxynitride film (SiON) orsilicon nitride film (SiN) etc., is used as a material for themicrolens, the microlens is likely to be displaced at an interfacebetween the inorganic film containing the microlens material and theorganic film formed below the inorganic film due to the difference inthermal expansion coefficient etc. (thermal expansion coefficient: theinorganic film<the organic film), depending on a thermal treatment stepin the manufacturing process of the solid-state image pickup deviceafter the formation of the microlens, or environmental conditions(particularly, high temperature, high humidity) after the manufacture ofthe solid-state image pickup device is completed. If the displacementoccurs, the sensitivity characteristics or color non-uniformitycharacteristics of the solid-state image pickup device is likely tovary, leading to deterioration of image quality.

Therefore, in order to achieve a smaller size, thinner size, andhigher-density implementation of video equipment, a wafer-level CSP isnewly devised and implemented as the structure of a solid-state imagepickup device, in order to achieve sensitivity characteristics which aregreater than or equal to those of conventional packages in which air ispresent on a conventional microlens even if an adhesive material isprovided on the microlens. A feature of the wafer-level CSP is that amicrolens including a plurality of layers of inorganic film, such asSiON, SiN, SiO, etc., which is formed, corresponding to each lightreceiving region of the solid-state image pickup element, is formed onan underlying film which has a projection-and-recess shape at least dueto the color filters. The microlenses are formed directly on the colorfilters which have a projection-and-recess shape, or on a non-planarfilm formed on the color filters which have a projection-and-recessshape. Also, the projection-and-recess shape can prevent thedisplacement of the microlens, whereby a structure of a solid-stateimage pickup device which does not have deterioration of image qualityand has high reliability, and a method for manufacturing the solid-stateimage pickup device, are provided.

Note that Patent Literatures 1 and 2 disclose methods for manufacturinga microlens made of inorganic film, such as SiN, SiON, etc.

Patent Literature 1 discloses a method for manufacturing a microlenswhich has a reduced gap between each microlens made of inorganic filmand a reduced distance between the photodiode and the microlens, therebyimproving the sensitivity characteristics of a solid-state image pickupelement.

In the method described in Patent Literature 1, which is a microlensmanufacturing method, a thermal mask layer (a material layer which willbe a microlens) made of an organic material which is formed in the topportion is deformed by a thermal treatment to form a microlens shapewhich has a gap between each microlens. A lens material layer (a layerwhich will be a microlens) made of an inorganic material is formed belowthe thermal mask layer, and thereafter, a middle layer made of anorganic material is provided between this mask layer and the lensmaterial layer. Patent Literature 1 discloses that, after etching themiddle layer under predetermined conditions into a mask layer having amicrolens shape having a gap between each microlens to provide a greatermiddle layer lens shape (a reduced microlens gap), the lens materiallayer made of an inorganic material, a microlens gap, is etched usingthe middle layer as a mask, whereby a microlens having an extremelyreduced gap between each microlens can be formed.

Also, Patent Literature 1 discloses that SiN and SiOSiON are applicableto the lens material layer made of an inorganic material. In this case,when SiN or SiON is selected as this material layer, the lightcollection power of the microlens is improved, and at the same time, thegap between each microlens is reduced, and the distance from thephotodiode to the microlens is reduced by transferring the mask layer tothe middle layer by etching and further continuing the etching, therebyimproving the light collection efficiency of the microlens.

However, because the shape is further transferred to the lens materiallayer through the middle layer by etching, it is likely to take a longertime to perform etching. This etching process is performed by plasmaetching, and therefore, the plasma damage is likely to adversely affectthe solid-state image pickup device. Specifically, the dark-currentcharacteristics etc. of the solid-state image pickup element is likelyto deteriorate due to the longer etching time. At the same time, thelonger processing time also increases variations in etching on asemiconductor wafer substrate surface or between wafer substrates, whichis likely to cause variations in the position in the cross-sectionaldirection of the microlens, leading to an adverse influence on thesensitivity characteristics etc. of the solid-state image pickupelement. Moreover, in addition to the processing time of the etchingdevice due to the longer wafer processing time, the formation of themiddle layer increases the number of steps, leading to the risk of anincrease in cost.

Moreover, Patent Literature 1 describes the color filters, but not thenumber of the colors. In the microlens manufacturing method includingthe long-time etching, it is likely to be difficult to adjust theposition in the height direction of the bottom portion of the microlens.

Also, Patent Literature 2 discloses a method for manufacturing amicrolens including two layers. In the microlens disclosed in PatentLiterature 2, SiO, SiN, or SiON is used as an inorganic material.Typically, the refractive index of SiN is about 1.85 to 2.0, and therefractive index of SiON is about 1.6 to 1.8. Therefore, these arehigher than the refractive index (about 1.5 to 1.6) of an acrylic-basedresin or a styrene-based resin which is typically used in a microlens,and therefore, can improve the light collection power of the microlens.

Such a microlens with high light collection power is a gapless microlenswhich is formed by adjusting the film formation of the microlens in thesecond layer so that there is not a gap between each microlens. However,when the micro in the second layer is formed so that a gap of themicrolens in the first layer having a gap is reduced, the position ofthe microlens which is finally formed is raised (further away from thephotodiode surface), and therefore, it is likely that the sensitivitycharacteristics etc. of a solid-state image pickup device in which thedistance between the photodiode and the microlens is reduced as in, forexample, a back-illuminated solid-state image pickup device, cannot beimproved.

Moreover, Patent Literature 2 discloses that the inorganic material usedin the microlens in the first layer and the microlens in the secondlayer can be selected from SiO, SiN, and SiON, but does not disclose therefractive index of each layer or the relationship between the filmthicknesses of the layers.

In order to improve the light collection characteristics of a microlens,it is necessary to consider the reduction of the gap between each lensand the distance from the photodiode (the layer thickness of FIG. 2),and in addition to these, the surface reflectance. However, PatentLiterature 2 does not disclose this relationship. Therefore, forexample, when SiO, which has a low refractive index, is selected as amaterial for the microlens in the first layer, and SiON, which has ahigh refractive index, is selected as a material for the microlens inthe second layer, the surface reflection of the microlens increases,leading to the risk of deterioration of the sensitivity characteristicsof a solid-state image pickup device.

Moreover, Patent Literature 2 discloses that the microlens should beformed on a planarized surface. Patent Literature 2 discloses that thereason is to remove the level difference caused by the color filters,and that a planarization layer is formed on the color filters. Also, theplanarization layer may not be formed. This seems to refer to the casewhere there is not a level difference caused by the color filters. Also,Patent Literature 1 does not describe a planarization film on the colorfilters. As shown in FIG. 1 of Patent Literature 1, a monochromaticcolor filter structure is shown, and therefore, it seems that there isnot a level difference caused by the color filters.

As described above, in both Patent Literature 1 and Patent Literature 2,color filters are included, and an interface between a planarizationfilm made of organic film formed on the color filters and microlensesmade of inorganic film formed on the planarization film seems to besubstantially planar.

Thus, when the interface between the inorganic film containing themicrolens material and the organic film formed below the inorganic filmis planar, the microlens is likely to be displaced due to the differencein thermal expansion coefficient between the materials, etc.

1-2 Lower Profile

Therefore, an image pickup element may include a non-planar layer whichhas a non-planar light incident surface in a light receiving region, anda microlens of an inorganic material which is provided on the lightincident surface of the non-planar layer, and collects incident light.

Also, the microlens may include a plurality of layers.

Moreover, the layers of the microlens including the plurality of layersmay have different refractive indices.

Also, the layers of the microlens including the plurality of layers mayhave different curved surface shapes.

Moreover, a portion of the layers of the microlens including theplurality of layers may be formed of an organic material.

Also, an anti-reflection film may be formed on a light incident surfaceof the microlens.

Moreover, the image pickup element may further include an adhesivematerial layer provided on a light incident surface of the microlens.

Also, the non-planar layer may have a filter.

Moreover, the filter may include filters with a plurality of colorshaving different thicknesses in a direction in which light passes.

Also, the filters having the different thicknesses may be arranged in aBayer arrangement, corresponding to red, green, and blue pixels, and thegreen filters may be linked between pixels.

Moreover, the filter may be formed of an organic material.

Also, the non-planar layer may have an organic film which is formed onthe filter and has a non-planar light incident surface.

Moreover, heights of projections and recesses of a light incidentsurface of the organic film may be lower than heights of projections andrecesses of a light incident surface of the filter.

Also, the refractive index of the organic film may be between therefractive index of the filter and the refractive index of themicrolens.

Moreover, the non-planar layer may have an inter-pixel light shieldfilm.

Also, the non-planar layer may have projections and recesses on thelight incident surface due to a difference in height between the filterand the inter-pixel light shield film.

Moreover, a chip size package structure may be formed.

Note that an image pickup device may include an image pickup elementwhich captures an image of an object, and outputs the image of theobject as an electrical signal, and an image processing unit whichprocesses the image of the object obtained by the image pickup element.The image pickup element may include a non-planar layer which has anon-planar light incident surface in a light receiving region, and amicrolens of an inorganic material which is provided on the lightincident surface of the non-planar layer, and collects incident light.

Moreover, a manufacturing device may include a non-planar layer formingunit which forms a non-planar layer having a non-planar light incidentsurface in a light receiving region of an image pickup element, aninorganic film forming unit which forms an inorganic film on the lightincident surface of the non-planar layer formed by the non-planar layerforming unit, a planarization film forming unit which forms aplanarization film on a light incident surface of the inorganic filmformed by the inorganic film forming unit, a resist forming unit whichforms a resist on a light incident surface of the planarization filmformed by the planarization film forming unit, a thermal reflow processunit which performs a thermal reflow process on the image pickup elementon which the resist has been formed by the resist forming unit, and anetching process unit which performs etching on the image pickup elementon which the thermal reflow process has been performed by the thermalreflow process unit.

Of course, a manufacturing method of the manufacturing device may beprovided.

Thus, not only a smaller size, thinner thickness, and higher-densityimplementation of video equipment can be achieved, but also, when awafer-level CSP is implemented as the structure of a solid-state imagepickup device, even if an adhesive material is provided on themicrolens, sensitivity characteristics which are greater than or equalto those of conventional packages in which air is present on aconventional microlens, can be obtained.

1-3 Image Pickup Device

A more specific example will be described. FIG. 3 is a diagram showingan example main configuration of an image pickup device. The imagepickup device 100 shown in FIG. 3, which may be included as an imagepickup element in another device, converts light from an object intoelectricity, and outputs an image of the object as an image signal.

The image pickup device 100 shown in FIG. 3 is formed to have the CSPstructure. The image pickup device 100 includes a solid-state imagepickup element which includes an image pickup region 121 which is formedon a semiconductor substrate 111 and on a surface of which a pluralityof color filters 132, a plurality of microlenses 133, and a plurality ofphotodiodes 131, etc., are provided, a peripheral circuit region 122which is formed in an outer peripheral region of the image pickup region121 of the semiconductor substrate 111, and a plurality of electrodeportions 123 formed in the peripheral circuit region 122.

Also, a transparent substrate 143 made of, for example, optical glassetc. is formed on a main surface of the solid-state image pickup elementabove the microlenses 133 with an adhesive material A 141 and anadhesive agent B 142 made of a resin-based material being interposedtherebetween. Moreover, on a back surface opposite to the main surfaceof the solid-state image pickup element, metal interconnects 125connecting to the plurality of electrode portions 123 in the peripheralcircuit region 122 are formed with through electrodes 124 penetratingthrough the semiconductor substrate in the thickness direction beinginterposed therebetween, and an insulating resin layer 126 which hasopenings which cover the metal interconnects 125 and expose a portionthereof is formed. External electrodes 127 made of, for example, asolder material are formed in the openings. Note that the solid-stateimage pickup element is electrically insulated from the throughelectrode 124 and the metal interconnect 125 by an insulating layer (notshown).

In the image pickup device 100, the plurality of electrode portions 123are electrically connected to the metal interconnects 125 through thethrough electrodes 124, and also, are electrically connected to theexternal electrodes 127 through the metal interconnects 125, andtherefore, a received light signal can be extracted.

A of FIG. 4 shows a plan view of the color filters 132 of red, green,and blue in a Bayer arrangement formed in the same light receivingregion of the solid-state image pickup element. Also, B of FIG. 4 showsa cross section (a side direction of the color filter 132) taken alongthe a-a′ direction in A of FIG. 4, and a cross section (a diagonaldirection of the color filter 132) taken along the b-b′ direction. Asshown in A of FIG. 4 and B of FIG. 4, the green color filters are linkedtogether at their four corners, and a red or blue color filter is formedin the openings of the green color filters.

Here, as shown in B of FIG. 4, the green color filters linked togetherat their four corners are formed to have a small thickness. Typically, amaterial for the color filter 132 used in the solid-state image pickupelement is provided by adding a pigment or a dye, which are colorants,into photo-polymerization negative photosensitive resin. Although it isdesirable that each color filter should be formed to have a pixel sizeof the solid-state image pickup element, the color filters 132 need tobe formed to overlap in order to ensure the cohesiveness of the colorfilters 132 or prevent the occurrence of a gap due to misalignment ofcolor filters of each color, etc. By forming the green color filterslinked together at their four corners, the cohesiveness can be improved,and the occurrence of a gap can be reduced.

Here, if the four corners of the green color filter are formed to have asufficient width, the pattern size increases, and therefore, the openingin which a red or blue color filter is to be formed is narrowed. Forexample, the green color filter enters a pixel in which a red or bluecolor filter should be formed, and the size of the red or blue colorfilter formed decreases, and as a result, the sensitivity with respectto blue or red decreases, or the color mixture of a green colorcomponent occurs, resulting in deterioration of characteristics of thesolid-state image pickup element.

In order to cause the green color filter size to be as close to thepixel size as possible, and ensure the cohesiveness, it is necessary toincrease the contact area, and in addition, form the color filters whileavoiding a break in the four corner linkage portions of the green colorfilter, and eliminating a gap between each of the red, green, and bluecolor filters. It is necessary to form the color filters using anexposure mask whose mask pattern size is smaller than or equal to thelimit of the resolution of the photosensitive resin during the formationof the color filters using photo-polymerization negative photosensitiveresin. Typically, the color filters are formed using the exposure masksize which is 200 nm or less during the formation of the four corners.When the photo-polymerization negative photosensitive resin is formedusing the exposure mask size which is smaller than or equal to the limitof the resolution, the photo-polymerization reaction is not sufficientlyperformed, so that that portion has a small film thickness (Δt).

As shown in A of FIG. 5 and B of FIG. 5, microlenses made of inorganicfilm are formed above the red, green, and blue color filters 132 thusformed in a Bayer arrangement shown in A of FIG. 4 and B of FIG. 4.

As described above, in the case of the conventional structure, as shownin A of FIG. 1 a thickness from the bottom surface of the color filterto the bottom surface of the microlens is t1, and as shown in B of FIG.1 a thickness from the bottom surface of the color filter to the bottomsurface of the microlens is t2.

In contrast to this, in the example of FIG. 5, although the colorfilters 132 have a level difference, a microlens including a singlelayer or a plurality of inorganic films is formed on the color filterwithout a planarization film (described below). Here, the thicknessesfrom the bottom surface of the color filter to the bottom surface of themicrolens in the a-a′ direction and in the b-b′ direction are t3 and t4.

Here, t1 and t2 are compared with t3 and t4. In the example of FIG. 1, abottom portion of the microlens is formed in the inorganic film. In theexample of FIG. 5, although a bottom portion of the microlens 133 issimilarly formed in the inorganic film, a planarization film is notformed, and therefore, the thicknesses have relationships t1>t3 andt2>t4, and the layer thickness can be reduced. In other words, in theexample of FIG. 5, the sensitivity characteristics of the solid-stateimage pickup element can be further improved.

Also, as shown by Δt in B of FIG. 5, the four corner portions of thegreen color filter can be formed to be thin, and therefore, thethickness can be proportionately reduced. Here, the bottom portion ofthe microlens in the b-b′ cross section is formed at a position wherethe green color filter is not exposed. This is because if the colorfilter 132 is exposed, the colorant contained in the color filter 132 isalso etched, so that the inner wall of the etching processing chamber ofthe etching device is stained with the colorant. If the inner wall ofthe etching processing chamber is stained, the influence of dust, metalcontamination in a metal-containing colorant, etc., causes a decrease inthe yield of the image pickup device 100.

Moreover, in the example of FIG. 1, by additionally applying etching tothe state shown, the distance from the bottom portion of the colorfilter 132 to the bottom portion of the microlens 133 can be reduced.However, in this case, as shown in B of FIG. 6, the microlens is formedwith the planarization film being exposed in the vicinity of the bottomportion of the microlens in the b-b′ cross-sectional direction.Therefore, the light collection power decreases in the bottom portion ofthe microlens in which the planarization film is exposed, due to therelationship of the refractive indices, leading to the risk ofdeterioration of the sensitivity characteristics of the solid-stateimage pickup element.

Note that, as shown in FIG. 7, a non-planar film 171 may be formed onthe color filter 132. In this case, an organic material or an inorganicmaterial is selected to form the non-planar film 171 so that a leveldifference Δa in FIG. 7 is reduced at the four corner portions of thegreen color filter. As the organic material, an acrylic-based resin, astyrene-based resin, an acrylic-styrene copolymer-based resin, etc. isused. The inorganic material is selected from silicon oxide film (SiO),SiON, SiN, etc. Here, by forming the non-planar film 171, the planarityof the microlens 133 made of inorganic film formed on the non-planarfilm 171 as it is formed is improved (Δa>Δb). Also, when, for thenon-planar film, an acrylic-based resin is selected from the organicmaterials, SiON is formed on an upper surface of the non-planar film.This is because when the microlens 133 is made of SiN, the occurrence ofcreases due to the difference in stress between the films is prevented.In order to prevent the occurrence of creases, a styrene-based resin oran acrylic-styrene copolymer-based resin, which has a higher cureddensity of film than that of acrylic-based resins, is used.

As described above, the non-planar film 171 is formed on the colorfilter 132, whereby the thickness from the lower portion of the colorfilter 132 to the lower portion of the microlens 133 is reduced. Even ifthe non-planar film 171 is exposed in the cross-section of the b-b′direction, the area where the non-planar film 171 is exposed is small,and therefore, the light collection power of the microlens 133 issubstantially equal to that of the structure shown in FIG. 5 etc.,leading to an improvement in the sensitivity of the solid-state imagepickup element. Moreover, when the non-planar film 171 is made of SiON,then if the refractive index is set to be between those of the colorfilter and the microlens, the interfacial reflection can be reduced,leading to a further improvement in the sensitivity characteristics or areduction in the flare characteristics.

For example, when the refractive index of the color filter 132 is about1.51 to 1.75, and SiN, which has a refractive index of about 1.9, isused as a material for the microlens, SiON is formed to have anintermediate refractive index therebetween by suitably adjustingconditions for the film formation.

Note that the microlens 133 may include a plurality of layers. Anexample of the structure will be described using FIG. 8. Note that FIG.8 shows an a-a′ cross section of A of FIG. 5. A multi-layer microlens181 shown in A of FIG. 8 has a first microlens layer 181-1 and a secondmicrolens layer 181-2. Each layer may have any of three configurationsshown in a table of FIG. 9.

Note that the refractive indices are assumed to have the followingrelative order of magnitude.

First Microlens≥Second Microlens

Also, a multi-layer microlens 182 shown in B of FIG. 8 has a firstmicrolens layer 182-1, a second microlens layer 182-2, and a thirdmicrolens layer 182-3. Each layer may have any of four configurationsshown in a table of FIG. 10.

Note that the refractive indices are assumed to have the followingrelative order of magnitude.

First Microlens Layer=Second Microlens Layer>Third Microlens Layer

Here, in the configurations of 2 and 4 (the first microlens layer=thesecond microlens layer>the third microlens layer), the second microlenslayer mainly acts to reduce gaps in the first microlens layer, and thethird microlens layer mainly functions as an anti-reflection filmincluding a single layer.

A multi-layer microlens 183 shown in C of FIG. 8 has a first microlenslayer 183-1, a second microlens layer 183-2, a third microlens layer183-3, and a fourth microlens layer 183-4. Each layer may have any oftwo configurations shown in a table of FIG. 11.

Note that the refractive indices are assumed to have the followingrelative order of magnitude.

Third Microlens Layer>First Microlens Layer=Second MicrolensLayer>Fourth Microlens Layer

Here, the second microlens layer 183-2 mainly acts to reduce gaps in thefirst microlens layer 183-1, and the third microlens layer 183-3 and thefourth microlens layer 183-4 mainly function as an anti-reflection filmincluding two layers.

In FIG. 11, as a material of (d), zirconium oxide (ZnO, refractiveindex: about 2.4), titanium oxide (TiO, refractive index: about 2.52),etc. may be used, and as a material of (e), silicon oxide film (SiO,refractive index: about 1.45), silicon oxycarbide film (SiOC, refractiveindex: about 1.4), magnesium fluoride (MgF, refractive index: about1.37), etc. may be used.

As described above, when the microlens 133 includes a plurality oflayers, a portion of the layers may be a microlens layer made of anorganic material.

For example, in the example of A of FIG. 8, an organic microlens may beformed as the first microlens layer 181-1, and an inorganic microlensmay be formed as the second microlens layer 181-2. In this case, eachmicrolens layer may have any of two configurations shown in a table ofFIG. 12.

Also, the refractive indices are assumed to have the following relativeorder of magnitude. Here, the refractive index of the organic microlenscan be adjusted according to the amount of fine metal oxide particlesadded.

First Microlens>Second Microlens

Here, the second microlens layer 181-2 mainly acts to reduce gapsbetween lenses in the first microlens layer 181-1.

For example, in the example of B of FIG. 8, an organic microlens may beformed as the first microlens layer 182-1, and inorganic microlenses maybe formed as the second microlens layer 181-2 and the third microlenslayer 181-3. In this case, each microlens layer may have any of fourconfigurations shown in a table of FIG. 12.

Also, the refractive indices are assumed to have the following relativeorder of magnitude. Here, the refractive index of the organic microlenscan be adjusted according to the amount of fine metal oxide particlesadded.

First Microlens Layer=Second Microlens Layer>Third Microlens Layer

Here, in the configurations of 2 and 4 (the first microlens layer=thesecond microlens layer>the third microlens layer), the second microlenslayer 182-1 mainly acts to reduce gaps in the first microlens layer182-1, and the third microlens layer 181-3 mainly functions as ananti-reflection film.

For example, in the example of C of FIG. 8, an organic microlens may beformed as the first microlens layer 183-1, and inorganic microlenses maybe formed as the second microlens layer 183-2, the third microlens layer183-3, and the fourth microlens layer 184-3. In this case, eachmicrolens layer may have any of two configurations shown in a table ofFIG. 14.

Also, the refractive indices are assumed to have the following relativeorder of magnitude. Here, the refractive index of the organic microlenscan be adjusted according to the amount of fine metal oxide particlesadded.

Third Microlens Layer>First Microlens Layer=Second MicrolensLayer>Fourth Microlens Layer

Here, the second microlens layer 183-2 mainly acts to reduce gaps in thefirst microlens layer 183-1, and the third microlens layer 183-3 and thefourth microlens 184-3 mainly function as an anti-reflection filmincluding two layers.

In FIG. 14, as a material of (d), zirconium oxide (ZnO, refractiveindex: about 2.4), titanium oxide (TiO, refractive index: about 2.52),etc. may be used, and as a material of (e), silicon oxide film (SiO,refractive index: about 1.45), silicon oxycarbide film (SiOC, refractiveindex: about 1.4), magnesium fluoride (MgF, refractive index: about1.37), etc. may be used.

2. Second Embodiment 2-1 Manufacturing Device

Next, a manufacturing device which manufactures the above-describedimage pickup device 100 (image pickup element) will be described.

FIG. 15 is a block diagram showing an example main configuration of adevice for manufacturing the image pickup device 100. A manufacturingdevice 200 shown in FIG. 15 has a control unit 201 and a manufactureunit 202.

The control unit 201, which has, for example, a CPU (Central ProcessingUnit), a ROM (Read Only Memory), and a RAM (Random Access Memory), etc.,controls each portion of the manufacture unit 202 to perform a controlprocess involved in manufacture of the image pickup device 100 (imagepickup element). For example, the CPU of the control unit 201 executesvarious processes according to programs stored in the ROM. Also, the CPUexecutes various processes according to programs loaded from a storageunit 213 to the RAM. The RAM also stores data which is required when theCPU executes various processes, etc., as appropriate.

The manufacture unit 202 is controlled by the control unit 201 toperform processes involved in manufacture of the image pickup device 100(image pickup element). The manufacture unit 202 has a light receivinginterconnect layer forming unit 231, a filter forming unit 232, a firstinorganic film forming unit 233, a planarization film forming unit 234,a resist pattern forming unit 235, a thermal reflow processing unit 236,an etchback process unit 237, a second inorganic film forming unit 238,and an etchback process unit 239. The light receiving interconnect layerforming unit 231 to the etchback process unit 239 are controlled by thecontrol unit 201 to perform processes of steps of manufacturing theimage pickup device 100 (image pickup element) as described below.

Note that, here, for the sake of convenience, only steps involved in thepresent technology will be described. Actually, in order to manufacturethe image pickup device 100 (image pickup element), other steps thanthose performed by these processing units are required. Although themanufacture unit 202 has processing units for those steps, those stepswill not be described herein in detail.

The manufacturing device 200 has an input unit 211, an output unit 212,a storage unit 213, a communication unit 214, and a drive 215.

The input unit 211, which includes a keyboard, a mouse, a touch panel,and an external input terminal, etc., receives input of, and supplies tothe control unit 201, a user's instruction or information from theoutside. The output unit 212, which includes a display, such as a CRT(Cathode Ray Tube) display or an LCD (Liquid Crystal Display) etc., aspeaker, and an external output terminal, etc., outputs various items ofinformation supplied from the control unit 201 as an image, audio, or ananalog signal or digital data.

The storage unit 213, which includes an SSD (Solid State Drive), such asa flash memory etc., or a hard disk, etc., stores information suppliedfrom the control unit 201, or reads and supplies stored information inaccordance with a request from the control unit 201.

The communication unit 214, which includes, for example, an interface ora modem, etc. for a wired LAN (Local Area Network) or a wireless LAN,performs a communication process with respect to an external devicethrough a network including the Internet. For example, the communicationunit 214 transmits information supplied from the control unit 201 to theother end of communication, or supplies information received from theother end of communication to the control unit 201.

The drive 215 is connected to the control unit 201 as required. And, aremovable medium 221, such as a magnetic disk, an optical disk, amagneto-optical disk, or a semiconductor memory, etc., is loaded intothe drive 215 as appropriate. And, a computer program read from theremovable medium 221 through the drive 215 is installed in the storageunit 213 as required.

2-2 Manufacturing Method

An example flow of the manufacture process will be described withreference to a flowchart of FIG. 16. Note that reference is made to FIG.17 as appropriate. FIG. 17 is a diagram for describing how each step ofthe manufacture process is performed.

When the manufacture process begins, in step S101 the light receivinginterconnect layer forming unit 231 is controlled by the control unit201 to form a light receiving layer, an interconnect layer, etc. on anN-type semiconductor substrate supplied from the outside.

In step S102, the filter forming unit 232 forms filters (A of FIG. 17).A of FIG. 17 shows the color filters 132 in a Bayer arrangement whichare formed corresponding to respective pixels of the image pickup device100. As a method for the color filter 132, a photosensitive resin intowhich, for example, a pigment or a pigment as a colorant is added isformed using photolithography. As the color filters 132, colormaterials, such as, for example, red, green, blue, etc., are formed. Inthis case, there is a level difference between adjacent color filters132.

In step S103, the first inorganic film forming unit 233 forms a firstinorganic film (B of FIG. 17). B of FIG. 17 shows the first microlenslayer 181-1 which is formed using P-CVD. In this case, the filmformation is performed under the following conditions: SiH4, NH3, N2O,and N2 are used as film formation gas if the first microlens layer 181-1is SiON, or SiH4, NH3, and N2 are used as film formation gas if thefirst microlens layer 181-1 is SiN; and the film is formed by P-CVD at atemperature of about 200° C., where the pressure etc. is adjusted asappropriate.

At this time, as to the film formation technique using P-CVD, for thefilm formation conditions, the mean free path during the film formationis adjusted, taking the level difference of the color filters 132 intoconsideration, so that the level difference is reduced.

Silicon nitride (SiN) film

-   -   gas: SiH4, NH3, N2    -   temperature: about 200° C.

Silicon oxynitride (SiON) film

-   -   gas: SiH4, NH3, N2O, N2    -   temperature: about 200° C.

pressure: 2 mTorr to 10 Torr

Here, the mean free path becomes gradually higher toward 2 mTorr andlower toward 10 Torr. Therefore, as to the planarity (Δh) after the filmformation of the first microlens layer in terms of the film thicknessratio of Tf and Tg shown in FIG. 18, Tg/Tf decreases when the firmformation is performed under pressure conditions which provide a highermean free path. As a result, the planarization film of resin can beformed to have a thin thickness as it is formed, and the first microlenscan be satisfactorily formed because of a slight difference in etchingselection ratio between the first microlens layer 181-1 and theplanarization film of resin during dry etching in the formation of thefirst microlens.

In step S104, the planarization film forming unit 234 forms aplanarization film (C of FIG. 17). As shown in C of FIG. 17, a middlefilm 401 which will be positioned between the first microlens layer181-1 and a photoresist pattern which will be next formed, is formed onthe first microlens layer 181-1. Here, the middle film 401 is formed ofa material which has a larger thermal expansion coefficient than that ofthe photoresist.

A photoresist pattern described below is formed on and made contact withthe middle film 401 having a larger thermal expansion coefficient thanthat of the resist, and thereafter, the resist is shaped into a lens bythermal reflow. As a result, the middle film 401 having a larger thermalexpansion coefficient than that of the photoresist can reduce a forcewhich is caused by the photoresist spreading during the thermal reflow,thereby reducing the amount of sliding of the photoresist pattern formedin contact with the middle film 401. Therefore, even if the length ofthe gap of the photoresist pattern is narrowed, adjacent resists are notin contact with each other, and therefore, the occurrence of a patterncollapse due to fusion can be prevented.

At this time, a film thickness 401 of the middle film is preferably 150nm or more in a thinnest region. If the film thickness is smaller thanor equal to this value, the effect which is obtained using thedifference in thermal expansion coefficient cannot be obtained, and thecontrollability of the lens shape is likely to deteriorate.

In step S105, the resist pattern forming unit 235 forms a resist pattern(D of FIG. 17). D of FIG. 17 shows a state in which a photoresistpattern 402 is formed on the first lens layer, corresponding to eachpixel of the image pickup device 100. As a positive photosensitiveresin, a material based on a novolac-based resin, a styrene-based resin,or a copolymer-based resin of these resins, is used.

Also, the pattern formation is performed using spin coating, prebake,i-line exposure, post-exposure bake, or a development process.

In step S106, the thermal reflow processing unit 236 performs a thermalreflow process (E of FIG. 17). As shown E of FIG. 17, the photoresistpattern 402 is baked by a thermal treatment at a temperature which ishigher than or equal to the thermal softening point. In this bakeprocess, a lens shape is obtained as shown in E of FIG. 17.

In step S107, the etchback process unit 237 performs an etching process(F of FIG. 17). F of FIG. 17 shows a state in which a photoresist 402having a lens shape is used as a mask to transfer the shape to the firstmicrolens layer 181-1 by etching. As to the etching process at thistime, a device, such as an ICP (Inductively Coupled Plasma) device, aCCP (Capacitively Coupled Plasma) device, a TCP (Transformer CoupledPlasma) device, a magnetron RIE (Reactive Ion Etching) device, an ECR(Electron Cyclotron Resonance) device, etc., is used as a plasmagenerating device, and a fluorocarbon gas-based gas, such as CF4, C4F8,etc., is used as a major component to perform the etching process whileadjusting the temperature, the pressure, etc. as appropriate. At thistime, as shown in F of FIG. 17 or G of FIG. 17, there is a gap betweenadjacent first microlens layers 181-1, and a gap shown in the b-b′cross-sectional view is larger.

In step S111, the second inorganic film forming unit 238 forms a secondinorganic film (G of FIG. 17). G of FIG. 17 shows a state in which afilm of SiN is formed as the second microlens layer 181-2. As a filmformation gas at this time, SiH4, NH3, and N2 are used, and the film isformed by P-CVD at a temperature of about 200° C., where the pressureetc. is adjusted as appropriate. At this time, as shown in the a-a′ b-b′cross-sectional views, the film is formed so that a gap between adjacentsecond microlens layers 181-2 is eliminated.

As to this film formation technique using P-CVD, the curvature of themicrolens 133 can be adjusted by adjusting the mean free path when a SiNor SiON film is formed as the second microlens layer 181-2. The specificfilm formation conditions are as follows.

Silicon nitride (SiN) film

-   -   gas: SiH4, NH3, N2    -   temperature: about 200° C.

Silicon oxynitride (SiON) film

-   -   gas: SiH4, NH3, N20, N2    -   temperature: about 200° C.

pressure: 2 mTorr to 10 Torr

The mean free path becomes gradually higher toward 2 mTorr and lowertoward 10 Torr.

By adjusting the mean free path as described above, the curvature of thesecond microlens layer 181-2 can be adjusted with respect to the firstmicrolens layer 181-1 having the same shape.

For example, as shown in A of FIG. 19, when the film is formed underconditions that the mean free path is relatively large, Tb/Tt decreasesand the curvature increases in the figure. As shown B of FIG. 19, whenthe mean free path is decreased, Tb/Tt increases and the curvaturedecreases. By adjusting the microlens curvature, not only microlenseswhich are applicable to CSP, but also microlenses which are applicableto various solid-state image pickup elements, can be formed.

Moreover, even when the first lens layer 181-1 has a non-curved surfaceshape as shown in FIG. 20, the second microlens layer 181-2 which iscorrected to have a shape similar to a curved surface can be formed byadjusting the film formation conditions.

In step S112, the etchback process unit 239 performs an etching process(H of FIG. 11).

Etchback is performed on the entire second microlens layer 181-2 whichhas been formed so that a gap between lens layers is eliminated, inorder to provide a low profile in a cross-sectional direction of thedevice. As to the etching process at this time, a device, such as an ICP(Inductively Coupled Plasma) device, a CCP (Capacitively Coupled Plasma)device, a TCP (Transformer Coupled Plasma) device, a magnetron RIE(Reactive Ion Etching) device, an ECR (Electron Cyclotron Resonance)device, etc., is used as a plasma generating device, and a fluorocarbongas-based gas, such as CF4, C4F8, etc., is used as a major component, toperform the etching process while adjusting the temperature, thepressure, etc. as appropriate. Thus, by performing etchback on the frontsurface, the bottom position of the microlens is lowered, whereby thesensitivity characteristics of the solid-state image pickup element areimproved.

When the process of step S109 ends, the manufacture process ends.

By performing the processes as described above, an image pickup elementwhich is manufactured so that deterioration of the sensitivitycharacteristics is reduced can be obtained.

As described above, a manufacturing method in which the inorganicmicrolenses 181 are formed as the first microlens layer 181-1 and thesecond microlens layer 181-2 is shown. Alternatively, the firstmicrolens layer 181-1 may be an organic microlens to which fine metaloxide particles are added.

As to a manufacturing method in which the first microlens layer 181-1 isan organic microlens, in the step of C of FIG. 17, for example, anorganic microlens material may be used which employs an epoxy-basedresin in which titanium oxide is added to fine metal particles. Thisorganic microlens is formed by spin coating followed by a thermaltreatment at about 150 to 200° C. In addition, the manufacturing methodis optimized as appropriate, as described above.

Also, as the microlens structure of the multi-layer microlens layer 182,main film formation conditions which are used when a silicon oxide (SiO)film is used are as follows.

Silicon oxide (SiO) film

-   -   gas: SiH4, N2O    -   temperature: about 200° C.    -   pressure: 2 mTorr to 10 Torr

Also, as a film formation method for the third microlens layer 183-3 andthe fourth microlens of the multi-layer microlens layer 183 of FIG. 8,vacuum vapor deposition, sputtering, ion vapor deposition, ion beam,mist CVD (Chemical Vapor Deposition), etc. is used.

2-3 Supplements

FIG. 21 shows a state in which the adhesive material A 141 shown in FIG.3 is formed on the microlens. As a material for the adhesive material A141, an acrylic-based resin (n=1.5) or a siloxane-based resin (n=1.42 to1.45) may be used, or in order to reduce the refractive index, fluorinemay be introduced to a side chain of the resin (n=1.4 to 1.44), orhollow silica particles may be added (n=1.3 to 1.39). Also, in thefigure, a SiON film having an intermediate refractive index betweenthose of the microlens and the adhesive material is formed, whereby theinterface reflection can be reduced. The reduction of the interfacereflection can lead to an improvement in the sensitivity characteristicsof the solid-state image pickup element, or a reduction in flare, etc.

Also, the adhesive material A 141 of FIG. 21 may also serve as theadhesive material B 142 of FIG. 3 (not shown). When the adhesivematerial A 141 also serves as the adhesive material B 142, the number ofinterfaces having different refractive indices is reduced, andtherefore, the reflection loss of incident light decreases. As shown inFIG. 22, the decrease of the reflection loss can lead to an improvementin the sensitivity characteristics of the solid-state image pickupelement, or a reduction in flare, etc.

Note that the present technology is not limited to chip size packages(CSPs). For example, a planarization film which has a lower refractiveindex than that of the microlens may be formed on the microlens, and asolid-state image pickup device may be packaged in a hollow form.

Also, the arrangement of the color filters 132 in the present technologyis not limited to a prime color Bayer arrangement. For example, a filterhaving any color and arrangement, such as a complementary color filter,a white (transparent) color filter, a black color filter, etc., can beused.

Also, a light shield film may be provided between pixels. For example,as shown in A of FIG. 23, an inter-pixel light shield film 452 may beprovided between pixels, and a filter of each color of buried colorfilters 441 may be buried in a light receiving portion of each unitpixel 451. In this case, as shown in B of FIG. 23 or C of FIG. 23,projections and recesses of the light incident surface are formed by thefilters and the inter-pixel light shield film 452.

Also, as shown in A of FIG. 24, a buried color filter 461 may beprovided on the inter-pixel light shield film. In this case, as shown inA of FIG. 24, the inter-pixel light shield film is not exposed on thelight incident surface.

As shown in B of FIG. 24 and C of FIG. 24, an inter-pixel light shieldfilm 472 is formed below the buried color filter 461. Therefore,projections and recesses of the light incident surface are formed by theburied color filter 461.

In any of the cases, similar to the foregoing, the microlens 133 can beformed.

3. Third Embodiment 3-1 Manufacturing Device

Note that the method for manufacturing the image pickup device is notlimited to the examples described above. For example, instead of formingthe non-planar film 171 which has been described with reference to FIG.7 by coating, the non-planar layer may be formed by etching.

FIG. 25 is a block diagram showing an example main configuration of amanufacturing device in that case. A manufacturing device 500 shown inFIG. 25, which is generally similar to the manufacturing device 200,manufactures the image pickup device 100. The manufacturing device 500has a control unit 501 and a manufacture unit 502, as with themanufacturing device 200.

The control unit 501, which is a processing unit which is similar to thecontrol unit 201, has a CPU, a ROM, and a RAM, etc., and controls eachportion of the manufacture unit 502 to perform control processesinvolved in manufacture of the image pickup device 100 (image pickupelement).

The manufacture unit 502, which is a processing unit similar to themanufacture unit 202, is controlled by the control unit 501 to performprocesses involved in manufacture of the image pickup device 100 (imagepickup element). The manufacture unit 502 has a light receivinginterconnect layer forming unit 531, a filter forming unit 532, aplanarization film forming unit 533, a first inorganic film forming unit534, a resist pattern forming unit 535, a thermal reflow processing unit536, an etchback process unit 537, an etchback process unit 538, asecond inorganic film forming unit 539, and an etchback process unit540. The light receiving interconnect layer forming unit 531 to theetchback process unit 540 are controlled by the control unit 501 toperform processes of steps of manufacturing the image pickup device 100(image pickup element) as described below.

Note that, here, for the sake of convenience, only steps involved in thepresent technology will be described. Actually, in order to manufacturethe image pickup device 100 (image pickup element), other steps thanthose performed by these processing units are required. Although themanufacture unit 502 has processing units for those steps, those stepswill not be described herein in detail.

The manufacturing device 500 has an input unit 511, an output unit 512,a storage unit 513, a communication unit 514, and a drive 515. The inputunit 511 to the drive 515 are processing units similar to the input unit211 to the drive 215, respectively, have similar configurations, andperform similar processes.

A removable medium 521 similar to the removable medium 221 is loadedinto the drive 515 as appropriate. A computer program read from theremovable medium 521 through the drive 515 is installed in the storageunit 513 as required.

3-2 Manufacturing Method

An example flow of the manufacture process will be described withreference to a flowchart of FIG. 26. Note that reference is made to FIG.27 as appropriate. FIG. 27 is a diagram for describing how each step ofthe manufacture process is performed.

When the manufacture process begins, in step S501 the light receivinginterconnect layer forming unit 531 is controlled by the control unit201 to form a light receiving layer, an interconnect layer, etc. on anN-type semiconductor substrate supplied from the outside.

In step S502, the filter forming unit 532 forms filters (A of FIG. 27).A of FIG. 27 shows color filters 132.

In step S503, the planarization film forming unit 234 forms aplanarization film 551 on the color filters 132 (B of FIG. 27). Theplanarization film 551 is formed of a material similar to that for thenon-planar film 171, and a surface of the planarization film 551 isfinally caused not to be planar, as with the non-planar film 171.Specifically, on the color filters 132, a non-planar layer having anon-planar surface, which is the planarization film 551 which has beenprocessed, is formed. Note that, during film formation, the non-planarlayer is formed as the planarization film 551 as described above.

In step S504, the first inorganic film forming unit 534 forms the firstmicrolens layer 181-1 as a first inorganic film on the planarizationfilm 551 (C of FIG. 27). The film formation conditions are similar tothose of the second embodiment. Note that, similar to the secondembodiment, the middle film 401 may be formed on the first inorganicfilm (the first microlens layer 181-1).

In step S505, the resist pattern forming unit 535 forms a resist pattern402 on the first inorganic film (the first microlens layer 181-1) (D ofFIG. 27).

In step S506, the thermal reflow processing unit 536 performs a thermalreflow process (E of FIG. 27). As shown in E of FIG. 27, the photoresistpattern 402 is baked by a thermal treatment at a temperature which ishigher than or equal to the thermal softening point. In this bakeprocess, a lens shape is obtained as shown in E of FIG. 27.

In step S507, the etchback process unit 537 performs an etching process(F of FIG. 27). F of FIG. 27 shows a state in which the photoresist 402having a lens shape is used as a mask to transfer the shape to the firstmicrolens layer 181-1 by etching. The etching process method at thistime is similar to that of the second embodiment described above withreference to F of FIG. 17.

As shown by dotted line circles c and d in F of FIG. 27, theplanarization film 551 is exposed by removing the first inorganic film(the first microlens layer 181-1) (e.g., SiN) at a peripheral portion ofthe microlens by etching. Here, by detecting C—O emission spectrumduring the etching, the controllability of a position where themicrolens is formed, in the height direction, can be further improved.

In step S508, the etchback process unit 538 performs an additionaletching process (G of FIG. 27). Specifically, the etchback process unit538 continues the dry etching performed in step S507. As a result, asshown by dotted line circles e or fin G of FIG. 27, level differences(projections and recesses) are formed on a surface of the planarizationfilm 551 on the color filters (CF) 132 at the peripheral portion of themicro T lens. Specifically, projections and recesses are formed on thesurface of the planarization film 551 to form a non-planar film 552.

At that time, the etchback process unit 538 may control the process timeof the etching process based on a time from reference time which is timewhen the etchback process unit 537 detects the C—O spectrum as describedabove. Thus, the etchback process unit 538 can more accurately control adepth of the level differences (projections and recesses formed).

Note that, in this etching process, the etchback process unit 538controls the process time so that projections and recesses are formed toan extent that the color filters 132 are not exposed.

In step S509, the second inorganic film forming unit 539 forms thesecond microlens layer 181-2 as a second inorganic film on the firstinorganic film (the first microlens layer 181-1) etc. which has beendry-etched (H of FIG. 27). H of FIG. 27 shows a state in which a film ofSiN is formed as the second microlens layer 181-2. The film formationconditions are similar to those of the second embodiment.

At this time, the second inorganic film (the second microlens layer181-2) is formed so that a gap between adjacent second microlens layers181-2 is eliminated as shown in the a-a′ b-b′ cross-sectional views. Asshown in the a-a′ b-b′ cross-sectional views, the second microlens layer181-2 is formed to an extent that a gap between adjacent secondmicrolens layers 181-2 is substantially eliminated. Note that a positionof an upper portion of the microlens in which the second inorganic film(the second microlens layer 181-2) is formed is represented by t₀.

In step S510, the etchback process unit 540 perform an etching processto an extent that the first inorganic film (the first microlens layer181-1) and the non-planar film 552 are covered by the second inorganicfilm (the second microlens layer 181-2), i.e., are not exposed (J ofFIG. 27).

This process causes the above position t₀ to be t₁, and therefore, a lowprofile is achieved in a cross-sectional direction. When the low profileis achieved, characteristics of the image pickup device 100 (imagepickup element) are improved.

When the process of step S510 ends, the manufacture process ends.

3-3 Image Pickup Element

By the above manufacture process, a microlens is formed on thenon-planar layer (the non-planar film 552) as shown in, for example,FIG. 28.

In this case, as shown in a dotted line circle 553 of A of FIG. 28 or ina dotted line circle 554 of B of FIG. 28, depressions (recesses) areformed on a surface of the non-planar film 552 in both the a-a′direction and the b-b′ direction, and the microlens is formed with aportion (end portion) thereof being buried in the depression (recess).In other words, the microlens is formed in the depression (recess) onthe surface of the non-planar film 552. The microlens of FIG. 28includes a plurality of layers, i.e., the first microlens layer 181-1and the second microlens layer 181-2. In the case of such a multi-layermicrolens, a portion (end portion) of at least one of the layers isformed in the depression.

With such a configuration, the displacement of the microlens which iscaused by a thermal treatment after the formation of the microlens,etc., can be reduced.

3-4 Manufacturing Device

Although, as described above, the depression (recess) on the surface ofthe non-planar film is formed in a peripheral portion of the microlens(pixel), it is not necessary that the depression (recess) should beformed in the entire peripheral portion, and the depression (recess) maybe formed in a portion of the peripheral portion. For example, thedepression (recess) may be formed only in a diagonal direction (the b-b′direction) of the pixel (i.e., only corners).

FIG. 29 is a block diagram showing an example main configuration of themanufacturing device in that case. As shown in FIG. 29, in this case,the manufacture unit 502 of the manufacturing device 500 has a secondinorganic film forming unit 561, an etchback process unit 562, and ananti-reflection film processing unit 563 instead of the etchback processunit 538 to the etchback process unit 540. These processing units arealso controlled by the control unit 501 to perform processes of steps ofmanufacturing the image pickup device 100 (image pickup element) asdescribed below.

3-5 Manufacturing Method

An example flow of the manufacture process will be described withreference to a flowchart of FIG. 30. Note that reference is made to FIG.31 as appropriate. FIG. 31 is a diagram for describing how each step ofthe manufacture process is performed.

When the manufacture process begins, processes of step S531 to step S537are executed in a manner similar to that of the processes of step S501to step S507 of FIG. 26.

Note that the etchback process of step S537 ends when a C—O emissionspectrum is detected. And, in step S538, the second inorganic filmforming unit 561 forms a second inorganic film (the second microlenslayer 181-2) to an extent that a gap of the microlens in thecross-sectional view in the a-a′ direction and the b-b′ direction issubstantially eliminated (A of FIG. 31). By performing the filmformation until a gap of the microlens is substantially eliminated, adifference in height between the a-a′ direction and the b-b′ directionoccurs in the pixel peripheral portion. For example, as shown in A ofFIG. 31, a position of an upper portion of the pixel peripheral portionin the a-a′ direction is represented by t₂, and a position of the upperportion of the pixel peripheral portion in the b-b′ direction isrepresented by t₃. In this case, the second inorganic film is formed sothat the position t₃ of the upper portion of the four corners of thepixel (the pixel peripheral portion in the b-b′ direction) is lower thanthe position t₂ of the upper portion of the pixel peripheral portion inthe a-a′ direction.

In step S539, the etchback process unit 562 performs an etchback processusing this height difference to form local depressions (recesses) on thesurface of the planarization film 551 (B of FIG. 31). As describedabove, the underlying organic film is reached earlier at sitescorresponding to the four corners of the microlens formed at a lowposition with respect to the cross-sectional direction. At this time,the etching process is carried out so that level differences are formedin the organic film (the planarization film 551) at at least the sitescorresponding to the four corners of the microlens.

In step S539, the anti-reflection film forming unit 563 forms ananti-reflection film 571 which is an inorganic film on a surface of eachlayer exposed by the etching process (dry etching) (C of FIG. 31). Thisinorganic film is selected from transparent materials which have arefractive index which reduces the surface reflection of the microlensmade of, for example, SiN, and has an intermediate refractive indexbetween those of the microlens material and a transparent film formed inan upper portion of the microlens material. Thus, this inorganic filmhas the function of resisting the displacement caused by a thermaltreatment in addition to the function of preventing the surfacereflection of the microlens.

When the process of step S539 ends, the manufacture process ends.

3-6 Image Pickup Element

By the above manufacture process, a microlens shown in FIG. 32 is formedon the non-planar layer (the non-planar film 552), for example.

In this case, as shown in A of FIG. 32, a depression is not formed onthe surface of the planarization film 551 in the a-a direction, i.e.,the planarization film 551 is not changed. In contrast to this, in theb-b′ direction, as shown B of FIG. 3, depressions (recesses) are formedon the surface of the planarization film 551 (a dotted line circle 572).Thus, the non-planar film 552 is formed. And, the anti-reflection film571 is formed in the depressions (recesses).

Therefore, similar to the case of FIG. 28, the displacement of themicrolens which occurs due to a thermal treatment after the formation ofthe microlens can be reduced. Also, as shown in FIG. 32, also in thiscase, a low profile is achieved in a cross-sectional direction. When alow profile is achieved, characteristics of the image pickup device 100(image pickup element) are improved.

Note that, in a structure in a cross-sectional view of the image pickupelement of each of the above examples, the microlens of inorganic filmis formed without exposing organic films, such as the color filtersetc., whereby damage on organic films, such as the color filters etc.,which is caused by external moisture can be reduced. As a result,deterioration of spectral characteristics etc. of the image pickupelement can be reduced.

3-7 Image Pickup Element

FIG. 33 is a diagram showing an example image pickup element. As shownin FIG. 33, typically, in a pixel region of the image pickup element 590in which pixels are formed, in addition to an image capture region 591(also referred to as an effective pixel region) which actually generatesa captured image, an outer peripheral region 592 is also formed aroundthe image capture region 591. This outer peripheral region 592 is, forexample, used as a margin for reducing variations in process, oralternatively, a light shield film which is used as an OPB region isformed in the outer peripheral region 592. The pixels of the outerperipheral region 592 have a configuration generally similar to those ofthe image capture region 591.

In the pixel region of the image pickup element 590 thus configured, notonly the pixels of the image capture region 591, but also the pixels ofthe outer peripheral region 592, may be configured so that the microlensof an inorganic material is formed on the non-planar layer as describedabove. Thus, the microlens is formed on the non-planar layer over awider range, and therefore, the displacement of the microlens whichoccurs due to a thermal treatment etc. can be further reduced.

Also, in that case, the pixels of the image capture region 591 and thepixels of the outer peripheral region 592 can be formed together by acommon process. As a result, the increase in time and effort of themanufacture process can be reduced, and the increase in cost can bereduced.

Note that, the above configuration in which the microlens of aninorganic material is provided on the non-planar layer may, for example,be provided only in a portion of the pixels, such as one row per severalrows or one pixel per several pixels.

The proportion may or may not be uniform over the entire pixel region.For example, only pixels in the outer peripheral region may have such aconfiguration.

4. Fourth Embodiment Image Pickup Device

FIG. 34 is a block diagram showing an example main configuration of animage pickup device. The image pickup device 600 shown in FIG. 34 is adevice which captures an image of an object, and outputs the image ofthe object as an electrical signal.

As shown in FIG. 34, the image pickup device 600 has an optical unit611, a CMOS sensor 612, an A/D converter 613, an operation unit 614, acontrol unit 615, an image processing unit 616, a display unit 617, acodec processing unit 618, and a recording unit 619.

The optical unit 611 includes a lens which adjusts a focal point to anobject and collects light from an in-focus position, a diaphragm whichadjusts exposure, and a shutter which controls timing of image capture,etc. The optical unit 611 allows light (incident light) from an objectto pass therethrough, and supplies the light to the CMOS sensor 612.

The CMOS sensor 612 perform photoelectric conversion on incident light,and supplies a signal (pixel signal) of each pixel to the A/D converter613.

The A/D converter 613 converts the pixel signal supplied from the CMOSsensor 612 with predetermined timing into digital data (image data), andsupplies the digital data sequentially to the image processing unit 616with predetermined timing.

The operation unit 614, which includes, for example, a jog dial(trademark), a key, a button, or a touch panel etc., receives anoperational input by the user, and supplies a signal corresponding tothe operational input to the control unit 615.

The control unit 615 controls drive of the optical unit 611, the CMOSsensor 612, the A/D converter 613, the image processing unit 616, thedisplay unit 617, the codec processing unit 618, and the recording unit619 based on a signal corresponding to an operational input of the userinput from the operation unit 614, to cause each unit to perform aprocess involved in image capture.

The image processing unit 616 performs various image processes, such as,for example, color mixture correction, black level correction, whitebalance adjustment, demosaicing, matrix processing, gamma correction,and YC conversion, etc., on image data supplied from the A/D converter613. The image processing unit 616 supplies the image data on whichimage processing has been performed, to the display unit 617 and thecodec processing unit 618.

The display unit 617, which is configured as, for example, a liquidcrystal display etc., displays an image of an object based on the imagedata supplied from the image processing unit 616.

The codec processing unit 618 performs a predetermined encoding processon the image data supplied from the image processing unit 616, andsupplies the resultant encoded data to the recording unit 619.

The recording unit 619 records the encoded data from the codecprocessing unit 618. The encoded data recorded in the recording unit 619is read out into and decoded by the image processing unit 616 asrequired. The image data obtained by the decoding process is supplied tothe display unit 617, which displays the corresponding image.

The present technology described above is applied to the CMOS sensor 612of the above image pickup device 600. Specifically, the above imagepickup device 100 is used in the CMOS sensor 612. Therefore, the CMOSsensor 612 can reduce deterioration of the sensitivity characteristics.Therefore, the image pickup device 600 can capture an image of anobject, thereby obtaining an image having higher image quality.

Note that the image pickup device to which the present technology isapplied is not limited to the above configuration, and may have otherconfigurations. In addition to, for example, a digital still camera anda camcorder, the image quality device may be an information processingdevice having the function of capturing an image, such as a mobiletelephone, a smartphone, a tablet device, a personal computer, etc.Also, the image pickup device may be a camera module which is attachedto another information processing device in use (or loaded as anembedded device).

5. Fifth Embodiment Computer

The above mentioned series of processes can, for example, be executed byhardware, or can be executed by software. In the case where the seriesof processes is executed by software, a program configuring thissoftware is installed in a computer via a network of from a recordingmedium.

The storage medium includes, as shown in FIG. 15, FIG. 25, and FIG. 29,for example, the removable medium 221 and the removable medium 521storing the program, which is distributed for delivering the program toa user independently from the apparatus. The removable medium 221 andthe removable medium 521 include a magnetic disk (including flexibledisk) and an optical disk (including CD-ROM and DVD), and furtherincludes a magneto optical disk (including MD (Mini Disc)), asemiconductor memory and the like. Alternatively, besides the removablemedium 221 or the removable medium 521, the above-described storagemedium may include ROM that stores the program, which is distributed tothe user in the form of being preliminarily installed in the apparatus,and a hard disk included in the storage part 213.

The expression “computer” includes a computer in which dedicatedhardware is incorporated and a general-purpose personal computer or thelike that is capable of executing various functions when variousprograms are installed.

FIG. 35 is a block diagram showing an example configuration of thehardware of a computer that executes the series of processes describedearlier according to a program.

In the computer 800 shown in FIG. 35, a central processing unit (CPU)801, a read only memory (ROM) 802 and a random access memory (RAM) 803are mutually connected by a bus 804.

An input/output interface 810 is also connected to the bus 804. An inputunit 811, an output unit 812, a storage unit 831, a communication unit814, and a drive 815 are connected to the input/output interface 810.

The input unit 811 is configured from a keyboard, a mouse, a microphone,a touch panel, an input terminal or the like. The output unit 812 isconfigured from a display, a speaker, an output terminal or the like.The storage unit 813 is configured from a hard disk, a RAM disk, anon-volatile memory or the like. The communication unit 814 isconfigured from a network interface or the like. The drive 815 drives aremovable medium 821 such as a magnetic disk, an optical disk, amagneto-optical disk, a semiconductor memory or the like.

In the computer 800 configured as described above, the CPU 801 loads aprogram that is stored, for example, in the storage unit 813 onto theRAM 803 via the input/output interface 810 and the bus 804, and executethe program. Thus, the above-described series of processing isperformed. The RAM 803 stores data in a suitable manner, which isnecessary for the CPU 801 to execute various processing.

Programs to be executed by the computer (the CPU 801) are applied beingrecorded in the removable medium 821 which is a packaged medium or thelike. Also, programs may be provided via a wired or wirelesstransmission medium, such as a local area network, the Internet ordigital satellite broadcasting.

In the computer, by loading the removable medium 821 into the drive 815,the program can be installed into the storage unit 831 via theinput/output interface 810. It is also possible to receive the programfrom a wired or wireless transfer medium using the communication unit814 and install the program into the storage unit 813. As anotheralternative, the program can be installed in advance into the ROM 802 orthe storage unit 813.

Note that the program executed by the computer may be a program in whichprocesses are carried out in a time series in the order described inthis specification or may be a program in which processes are carriedout in parallel or at necessary timing, such as when the processes arecalled.

Note that, in this specification, steps that write the program to berecorded in the recording medium do not necessarily have to be performedin time series in line with the order of the steps, and instead mayinclude processing that is performed in parallel or individually.

Further, in the present disclosure, a system has the meaning of a set ofa plurality of configured elements (such as an apparatus or a module(part)), and does not take into account whether or not all theconfigured elements are in the same casing. Therefore, the system may beeither a plurality of apparatuses, stored in separate casings andconnected through a network, or a plurality of modules within a singlecasing.

Further, an element described as a single device (or processing unit)above may be divided to be configured as a plurality of devices (orprocessing units). On the contrary, elements described as a plurality ofdevices (or processing units) above may be configured collectively as asingle device (or processing unit). Further, an element other than thosedescribed above may be added to each device (or processing unit).Furthermore, a part of an element of a given device (or processing unit)may be included in an element of another device (or another processingunit) as long as the configuration or operation of the system as a wholeis substantially the same.

It should be noted that the program executed by a computer may be aprogram that is processed in time series according to the sequencedescribed in this specification or a program that is processed inparallel or at necessary timing such as upon calling.

For example, the present disclosure can adopt a configuration of cloudcomputing which processes by allocating and connecting one function by aplurality of apparatuses through a network.

Further, each step described by the above mentioned flow charts can beexecuted by one apparatus or by allocating a plurality of apparatuses.

In addition, in the case where a plurality of processes is included inone step, the plurality of processes included in this one step can beexecuted by one apparatus or by allocating a plurality of apparatuses.

Additionally, the present technology may also be configured as below.

(1)

An image pickup element including:

a non-planar layer having a non-planar light incident surface in a lightreceiving region; and

a microlens of an inorganic material which is provided on a side of thelight incident surface of the non-planar layer, and collects incidentlight.

(2)

The image pickup element according to (1), wherein

the microlens includes a plurality of layers.

(3)

The image pickup element according to (2), wherein

the layers of the microlens including the plurality of layers havedifferent refractive indices.

(4)

The image pickup element according to (2) or (3), wherein

the layers of the microlens including the plurality of layers havedifferent curved surface shapes.

(5)

The image pickup element according to any one of (2) to (4), wherein

at least a portion of the layers of the microlens including theplurality of layers is formed in a recess portion of the non-planarlayer.

(6)

The image pickup element according to any one of (1) to (5), wherein

an anti-reflection film is formed over a light incident surface of themicrolens.

(7)

The image pickup element according to any one of (1) to (6), furtherincluding:

an adhesive material layer provided on a side of a light incidentsurface of the microlens.

(8)

The image pickup element according to any one of (1) to (7), wherein

the non-planar layer has a filter.

(9)

The image pickup element according to (8), wherein

the filter includes filters with a plurality of colors having differentthicknesses in a direction in which light passes.

(10)

The image pickup element according to (9), wherein

in the filter, filters having different thicknesses and corresponding tored, green, and blue pixels, are arranged in a Bayer arrangement, andthe green filters are linked between pixels.

(11)

The image pickup element according to any one of (8) to (10), wherein

the filter is formed of an organic material.

(12)

The image pickup element according to any one of (8) to (11), wherein

the non-planar layer has an organic film which is formed on the filterand has a non-planar light incident surface.

(13)

The image pickup element according to (12), wherein

heights of projections and recesses of a light incident surface of theorganic film are lower than heights of projections and recesses of alight incident surface of the filter.

(14)

The image pickup element according to (12) or (13), wherein

the refractive index of the organic film is between the refractive indexof the filter and the refractive index of the microlens.

(15)

The image pickup element according to any one of (8) to (14), wherein

the non-planar layer has an inter-pixel light shield film.

(16)

The image pickup element according to (15), wherein

the non-planar layer has projections and recesses on the light incidentsurface due to a difference in height between the filter and theinter-pixel light shield film.

(17)

The image pickup element according to any one of (1) to (16), wherein

a chip size package structure is formed.

(18)

An image pickup device including:

an image pickup element which captures an image of an object, andoutputs the image of the object as an electrical signal; and

an image processing unit which processes the image of the objectobtained by the image pickup element,

wherein the image pickup element includes

-   -   a non-planar layer which has a non-planar light incident surface        in a light receiving region, and    -   a microlens of an inorganic material which is provided on a side        of the light incident surface of the non-planar layer, and        collects incident light.        (19)

A manufacturing device including:

a non-planar layer forming unit which forms a non-planar layer having anon-planar light incident surface in a light receiving region of animage pickup element;

an inorganic film forming unit which forms an inorganic film on a sideof the light incident surface of the non-planar layer formed by thenon-planar layer forming unit;

a planarization film forming unit which forms a planarization film on aside of a light incident surface of the inorganic film formed by theinorganic film forming unit;

a resist forming unit which forms a resist on a side of a light incidentsurface of the planarization film formed by the planarization filmforming unit;

a thermal reflow process unit which performs a thermal reflow process onthe image pickup element on which the resist has been formed by theresist forming unit; and

an etching process unit which performs etching on the image pickupelement on which the thermal reflow process has been performed by thethermal reflow process unit.

(20)

A method for manufacturing a manufacturing device which manufactures animage pickup element, the method including:

by the manufacturing device,

-   -   forming a non-planar layer having a non-planar light incident        surface in a light receiving region of an image pickup element,    -   forming an inorganic film on a side of the light incident        surface of the non-planar layer formed,    -   forming a planarization film on a side of a light incident        surface of the inorganic film formed,    -   forming a resist on a side of a light incident surface of the        planarization film formed,    -   performing a thermal reflow process on the image pickup element        on which the resist has been formed, and    -   performing etching on the image pickup element on which the        thermal reflow process has been performed.

REFERENCE SIGNS LIST

-   100 image pickup device-   121 image pickup region-   132 color filter-   133 microlens-   171 non-planar film-   200 manufacturing device-   202 manufacture unit-   231 light receiving interconnect layer forming unit-   232 filter forming unit-   233 first inorganic film forming unit-   234 planarization film forming unit-   235 resist pattern forming unit-   236 thermal reflow process unit-   237 etchback process unit-   421 anti-reflection film-   441 buried color filter-   452 inter-pixel light shield film

The invention claimed is:
 1. An imaging device comprising: a non-planarlayer composed of color filters, the color filters are an organicmaterial; and microlenses touching the color filters, the microlensesare an inorganic material, wherein the inorganic material of themicrolenses touches the organic material of the color filters, andwherein a thickness from a bottom surface of the color filters to abottom surface of the microlenses in a side direction of the colorfilters is larger than a thickness from a bottom surface of the colorfilters to a bottom surface of the microlenses in a diagonal directionof the color filters.
 2. The imaging device according to claim 1,wherein the color filters are between the microlenses and photodiodes.3. The imaging device according to claim 1, wherein no planarizationlayer is between the microlenses and the color filters.
 4. The imagingdevice according to claim 1, wherein no other material is between anyportion of the microlenses and any portion of the color filters.
 5. Theimaging device according to claim 1, wherein the organic material is astyrene-based resin.
 6. The imaging device according to claim 1, whereinthe organic material is an acrylic-styrene copolymer-based resin.
 7. Theimaging device according to claim 1, wherein the organic material is aphotosensitive resin.
 8. The imaging device according to claim 1,wherein the organic material is a negative photosensitive resin.
 9. Theimaging device according to claim 1, wherein the inorganic material is asilicon oxide.
 10. The imaging device according to claim 1, wherein theinorganic material is a silicon oxynitride.
 11. The imaging deviceaccording to claim 1, wherein the inorganic material is a siliconnitride.
 12. The imaging device according to claim 1, wherein a firstsurface of the non-planar layer is between a first surface of themicrolenses and a second surface of the non-planar layer.
 13. Theimaging device according to claim 12, wherein a second surface of themicrolenses is between the first surface of the microlenses and thefirst surface of the non-planar layer.
 14. The imaging device accordingto claim 12, wherein the first surface of the non-planar layer touchesthe second surface of the microlenses.
 15. The imaging device accordingto claim 1, wherein along a side direction in a plan view of the colorfilters, a first one of the color filters is between a second one of thecolor filters and a third one of the color filters.
 16. The imagingdevice according to claim 15, wherein along a diagonal direction in theplan view of the color filters, the first one of the color filters isbetween a fourth one of the color filters and a fifth one of the colorfilters.
 17. An imaging apparatus comprising: the imaging deviceaccording to claim 1; a lens; and an image processor.